Abigail BanerjiFeb 26, 2021 9:17:26 AM IS
With ‘Ms Rona’, better known as the coronavirus, celebrating her first anniversary since coming into our lives, terms like pandemic, PPE, antibodies, antigens, etc. have grown in demand and popularity, and are now part of our daily vocabulary. Many of us may now understand the complex process of a vaccine being developed, the clinical trials it goes through, and the regulatory approvals it needs before it is rolled out. We have lived and we have learned.
With the SARS-CoV-2 virus rapidly ‘mutating’, new ‘variants’ of the virus have emerged in many parts of the world. In the pre-COVID-19 era, we may have used this new piece of information to impress friends or family over dinner or cocktails. But let’s face it, the variants in question probably aren’t going to let that happen anytime soon.
Then let’s dive deep and understand the basics …
What is a virus?
Before the COVID-19 pandemic, we had vaguely heard of viruses causing illnesses such as Ebola in Guinea and Congo, Swine Flu or Avian Flu in India and Russia, AIDS, etc. We now know that the SARS-CoV-2 virus causes COVID . -19 disease.
According to a report by Scientific Americanthe scientific community has debated the definition of a virus for years; first as a poison, then as a life form, then as a biological chemical.
Today viruses are considered to be somewhere between a living and a non-living being.
A virus consists of a core of genetic material (DNA or RNA) surrounded by a protective layer of protein. They can cling to host cells and use the host cell’s machinery to replicate the genetic material. Once this replication process is complete, the virus leaves the host by either budding or bursting out of the cell, destroying it in the process.
Viruses cannot replicate themselves, but once they attach to a host cell, they can thrive and affect host cell behavior in a way that harms the host and benefits the virus.
What is a kind?
Kind of, according to a report The conversation, is a variant that is built differently, exhibits different physical characteristics and behaves differently from the original virus. These behavioral differences can be subtle or obvious.
Coronaviruses, such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), are riddled with protein spikes that attach to receptors on their victims’ cells. The SARS-CoV-2 is now one of the few other known strains in the coronavirus family, including the SARS and MERS virus.
Experts believe the term strain is often misused.
“There is one coronavirus strain. That’s SARS-CoV-2. That’s the single strain, and there are variants of that strain.” The independent quoted Professor Tom Connor from the School of Biosciences at Cardiff University.
What is a mutation?
A virus consists of a sequence of either DNA or RNA, which is basically a string of nucleotide letters that code for genes in all living things. Any change in these letters is called a mutation and occurs when a virus sequence replicates itself. Mutations occur very randomly in a virus – a fact that could work for or against us in a pandemic scenario. A mutation can benefit the virus and make it stronger, or it can be harmful and reduce virulence.
SARS-COV-2, unlike the influenza virus, has a protein known as a proofreading enzyme. The enzyme is similar to what a text editor does in a newspaper, which is to check for spelling errors on a page. This enzyme will make corrections based on the original virus sequence. So if changes have occurred due to a random mutation, it will try to correct them.
As with a human copy editor, sometimes a mutation will pass and stay through the proofreading enzyme. As the mutant virus particle replicates, the entire genome, including the site of the mutation, is duplicated and transferred by future generations of the virus.
So, how does someone know if the virus has mutated? That’s where a virologist comes into play. Virologists have worked tirelessly to find out all the variants that infect humans. The original virus, found in Wuhan, is used to compare with the mutating coronavirus variants.
What is a variant?
Simply put, “a variant is a version of the virus that has accumulated enough mutations to represent a separate branch in the family tree”, says infectious disease expert Dr. Amesh Adalja Senior Scholar at the Johns Hopkins Center for Health Security.
Every mutation and strain of a virus is a variant, but not every variant is a strain.
Most variants are not a cause for concern. This is because the mutations did not drastically change the virus in question. However, when a lot of mutations have taken place, it can sometimes affect the way the virus behaves, spreads, or infects people. Then a variant becomes a ‘variant of care’. A classic example is the new variants spreading across parts of the UK, Africa and Brazil.
Scientists are closely monitoring the variants of SARS-CoV-2 to understand how genetic changes in the virus may affect infectivity (and thus spread), disease severity, treatment and effectiveness of the available vaccines. says Dr. Thomas Russo, professor and chief of infectious diseases at the University of Buffalo in New York.
What are the new variants in circulation?
A variant of SARS-CoV-2, known as B.1.1.7, has been spreading across the UK since December 2020, and now cases are popping up around the world. Scientists have found some evidence that this variant has an increased risk of death compared to other variants.
An infographic that tells about the latest SARS-CoV-2 variants that are spreading. Image credit: European Center for Disease Prevention and Control
In South Africa, another variant of SARS-CoV-2, known as B.1.351, emerged. It has some similarities to the UK variant and can also re-infect people who have recovered from other COVID-10 variants. There is also some evidence that the AstraZeneca and Moderna vaccine is not as effective against this variant.
A variant known as P.1 has surfaced in Brazil and was first discovered in humans traveling from the South American country to Japan. There is some evidence that this variant can affect the way antibodies react with the virus. The mutation of the P.1 variant causes the antibodies to no longer recognize and neutralize the virus.
According to the CDC, all three of these variants share one specific mutation called D614G, which allows it to spread faster.
With new variants popping up all the time, it’s important that we’re on top of our genome sequencing game. By doing this, we will be able to find and anticipate new variants of public health significance (as they may be more contagious, cause more serious diseases, develop a vaccine, or develop immune resistance). However, ignoring these emerging new mutations will not make them go away and can be harmful to us in the long run.